This article describes the impact of the Italian electoral reforms of 1993 on the structure of political alliances. The reform, which moved Italy from a pure proportional representation system to a mixed largely majoritarian system, was designed to increase transparency, reduce corruption, limit the number of political parties, and create the conditions for a politics of interests, rather than a politics of influence. Paradoxically, moving to a mixed electoral system had the opposite effect. In this article, the authors demonstrate this impact, by modeling the structure of political alliances at multiple levels (municipal, provincial, and regional) of the Italian polity from 1986 to 2001, from data on roughly 441,000 persons elected to serve in almost 3 million positions.